Based on a quick search, this is the DIRECT LINK to your computers Audio Drivers. I want to caution you that this link came from the manufacturer Acer, and may not work for your specific model. I did download the file myself, and it seems to be as it says.
Harrison Whitmarsh,what to do for using viber on my windows 8.1
recently i have installed viber on my pc
but when i call someone, i can watch but cant hear. anothr problem is when i start viber ,my sound mixer becomes 2 part from one what is the problem ???? can you tell me????
Sadly, I have never used that program before. Firstly, I would go into Device Manager (devmgmt.msc in Run) and make sure that all of your devices have the correct Drivers installed. If all of your drivers are working properly, then it must just be a setting in the software itself that is causing your issue. In this case, its kind of hard to judge your problem due to the software you are using.